The present disclosure relates to methods and apparatus for an atomic layer deposition (ALD) chamber. In one embodiment, a lid assembly is provided that includes a multi-channel showerhead having a plurality of first gas channels and a plurality of second gas channels that are fluidly isolated from each of the first gas channels, and a flow guide coupled to opposing sides of the multi-channel showerhead, each of the flow guides being fluidly coupled to the plurality of second gas channels.